Aegon beat expectations for its second quarter underlying pretax profit, while Coca Cola HBC shares hit a record level after first half sales were higher than expected.

"Aegon released a very strong set of Q2 results marked by a significant increase in the group SII ratio, strong underlying earnings and an improved outlook for capital generation," analysts at KBC Securities said in a note.

Telecoms company SFR jumped 9.2 per cent after Altice raised its stake in the firm to more than 95 per cent and said it was planning a full buyout offer for the remaining shares.

Second-quarter results, however, put pressure on shares in staffing firm Adecco, chemicals company Lanxess and consumer group Henkel, which were among the biggest fallers.

Around 80 per cent of MSCI Europe firms have reported second quarter earnings so far, of which more than 60 per cent have either met or beaten analysts' expectations, according to Thomson Reuters data.

Financials and the energy and materials sectors have seen the most beats, while industrials have had the most misses.

"Broadly in Europe, I had thought that (earnings) wouldn't be as good, partly because the strength of the euro would make (firms') export markets less attractive and earnings would be more impinged by that, but it doesn't so far seem to be the case," said James Butterfill, head of research and investment strategy at ETF Securities.

Societe Generale analysts said the relationship between the euro and euro zone stocks had flipped (see chart below).

"In the first part of the year, both the euro and euro zone equity markets were up, as the two assets were driven by a stronger economic outlook for the euro area," they said in a note.

"Since mid-May, the correlation has changed: the euro strengthening has become a headwind for the Eurostoxx index."

Shares in Belgian biotech firm Galapagos were among top risers on the Stoxx index, surging 8 per cent after a successful mid-stage study for the firm's lung fibrosis drug.